Micro-bead and nanophase carbon materials have applications in high-density and high-strength carbon artifacts, super active carbon beads of high surface area, lithium storage, lithium battery anodes, packing materials for high performance liquid chromatography, hydrogen storage applications, and catalysis. Much attention has been focused on the preparation and properties of these materials because their applications depend on the shape and size of the particles.
Carbon nitrides are extremely materials. They have low density, are extremely wear resistant, and are generally chemically inert. Carbon nitrides are used in biocompatible coatings on biomedical implants, battery electrodes, catalytic supports, gas separation systems, electronic materials, humidity and gas sensors, and other applications. Applications of carbon nitrides are governed not only by the texture and size of the particles but also by the relative nitrogen content. As a consequence, an extensive effort has been focused on carbon nitride precursors and on methods to increase the nitrogen content of carbon nitrides.
Publications related to the preparation of carbon nanospheres and nitrogen-rich carbon nitrides (i.e. carbon nitrides where the weight percent of nitrogen is greater than about 60 percent) are scarce. Gillan et al., for example, reported the preparation of carbon nitrides C3N4 (60.9 wt % N) and C3N5 (66.0 wt % N) and graphitic carbon using high-nitrogen precursor 2,4,6-triazido-1,3,5-triazine (see: Gillan, Chem. Mater., vol. 12, (2000) pp. 3906-3912, incorporated by reference). Also, Lee et al. recently reported a preparation of an aggregate interlinked network of carbon nanospheres from naphthalene-derived isotropic pitch using a lengthy five-step process of acidification, extraction, stabilization, oxidation, and carbonization (see: Lee et al., Carbon, vol. 41, (2003) pp. 1652-1654, incorporated by reference). Through mild grinding, carbon nanospheres having dimensions ranging from about 100 to about 300 nm were individually separated.
There remains a need for better methods for preparing carbon nitrides and precursors for carbon nitrides.